Effect of different mixtures of organic substrates on the biomass and essential oil of Thymus zygis

Abstract

In this trial we evaluated the effect of different mixtures of organic growing media substratum and vermicompost and their physical properties on biomass, chemical composition and yield of essential oils of Thymus zygis. Five treatments were established based on two types of organic materials (O, commercial growing media, and V, vermicompost). The following proportions were studied (v/v): V100 (100%V); VO75-25 (75%V+25%O); VO50-50 (50%V+50%O); VO 25-75 (25%V+75%O) and O100 (100%O).

The inclusion of vermicompost did not improve biomass production. The treatment O100 produced more biomass and the lowest was obtained in VO25-75. On V100 treatment all plants were dead and also have showed the highest pH and particle density and conversely presented the lowest value of total pore space.

Oxygenated monoterpenes predominated in the oils extracted from plants in O100 and VO25-75, contrary to what was found for non-oxygenated monoterpenes having these prevailed in VO75-25 and VO50-50. The concentration of thymol was high in the mixtures tested, particularly in VO25-75.